A variety of reusable straw assemblies are known in the art for use in drinking cups. Flexible elastomeric straws made of various materials, such as silicone, have been used, as have two piece straw assemblies. The latter typically consist of a lower straw mounted on the underside of a lid and an upper straw mounted on the top of a lid, to form an integral straw assembly. Straws having various elements preventing their accidental removal from the cup, such as lips, collars on the outside of the cup lid, and the like, are also known.
Nonetheless, most of these designs are laborious and time-consuming to assemble, difficult to clean, and of limited durability.
The art has also failed to provide a straw assembly optimally suited for use in a spillproof drinking cup of the type disclosed in U.S. Pat. No. Des. 366,809 to Green or U.S. Pat. No. 5,273,172 to Rossbach et al., which are licensed to the assignee of the present invention. These cup assemblies include a cup, a threaded or snap-on lid, a hole through the lid to accept a straw, and a cap mounted on the lid and rotatable about a horizontal axis to fold, seal and enclose the protruding top of the straw.
A typical disposable plastic straw could be used in these cup assemblies. The drawbacks of such a straw are evident. The plastic would rapidly be weakened and split by the bending motion required in the sealing cap. A standard straw would have to be cut to fit the dimensions of the cup and sealing cap. Furthermore, a standard straw would tend to slip and rest directly on the bottom of the cup, limiting the suction action of the straw. In addition, the straw could be difficult to insert through the hole in the lid without bending and buckling. The sealing action of these cups also would be limited by the thin, semi-rigid walls of the straw. Only a partial seal would be effected.